Gear shifting mechanism



March 15, 1932. F. A. PEARSON 1,849,882

GEAR SHIFTING MECHANISM v Filed Aug. '7, 1929 28heets-Sheei 1 am a,

INVE NTOR. firfafxP/clr/q Pzwmsow (Z/AM ATTORNEY March 15, 1932. F..A.PEARSON I 1,849,882

GEAR SHIFTING MECHANISM Filed Aug. 7, 1929 2 Sheets-Sheet I N INVENTOR.fkzwf/r/or ,4 I A-'fl/FJON ATTORNEY '45 nism illustrated inFig. 1; and

Patented Mar. 15, 1932 warren STATES IREDERIGK .A. PEARSON, OFGREATIZBABRINGTON, MASSACHUSETTS I GEAR SHIFTING .ME CHAN-ISMApplication'filed August 7, 1929. iSeria1No,.13'84,,033.

The present invention relates in general to power transmission systemsand particularly to transmission systems including a shifting mechan ismhaving provisions for selectively engaging a driving-element with one ofa plurality -of driven elements normally out 'of engagement with butadapted to be operatively connected thereto. The general object of In-yinvention is to provide an im- {proved construction and mode'ofoperation 'o'fa shi ftingmechanismcharadterizedby the simplicity andeffectiveness of the provisions for controllingthe operation-of theshifting mechanism and by means for facilitating the engagement of thedriving and driven elements.

While certain features'ofmy invention are adapted for use in varioustypes of power transmission and control systems, the apparatus of myinvention is especially useful when incorporated in transmissionapparatus lof thecharacter illustrated in my prior application SerialNo. "3215053, filed November 22, 1928, and 'wi ll 'be describedinconnection with a system of that general type.

The various features of novelty which characterize my invention 7 arepointed out with particularity in-the claims annexed to and-formin-gapartof this specification. For

a' betterunders'tanding Of'tllGiIlVGIltiOIl, 'however, and theadvantages possessed by it reference should be had to the accompanyin'r'lrawings and descriptive matter in which have illustrated anddescribeda preferred em- :b odiment of the invention. 7 I

Of the drawings: i

Fig. l is a sec'tiona'lelevation of one embodiment of 'my invention withcertain parts diagrammatically illustrated;

'40 Figs. Q and-B are vertical sectionson the line 2-12 and 3-3,respectively, :of Fig. 1; Fig. l isaisection on' the'line44 of Fig. lwith parts broken =away;

=Fig. 5is end view ofthe control mecha- -6 is an-enlarged elevationpartly in section of a portion of the worm illustrated in Fig.1. r

In the drawings lhave illustrated :a preferred *form of my invention as"incorporated "o'fithe drive shaft B. =ThetshaftsrC andD $335 and itheir:respectiv'e gears are spaced :a predetermined distance from a neutralip'OSl'ti'OIl :of'the driveshaftand may beisepa'rat'ely'connectedatoawork performing mechanism :(not shown) or preferably as :shown;"intercomnectecl :by sprocket 'wheels 6 and 1E :and an end-less chain GThe drive shaft ,is :arranged :to be shifted from a' neutral'idlingposition to the extreme upper and rlower engaging p ositions indicatedby the ifull 5W5 broken lines, respectively, in Fig. :1 :and :can

he moved directly from one extreme position :to the otherea'shereinafter iiescribed.

"The mechanism :byzmeans of. which tlIPDP'O- sition of the i drive shaftis :shifted comrises' %0 a' cup :sha'ped casingihav'ingia hub portion Esecured to' the 'free end coif the drive :shaft B. The portion liof thecasing hub adjacent the end of the :drive shafthas a crecesst il inwhichthe outerracerF of aballabearirrglF is 7535 mounted. The'enlarge'douter end of the easing is formed with an inner peripheral recess .E 'inwhich -is secured an internal :gear forminga part :of a planetary igearsystemd Asillusflated in Figs; 51 and:2,:the?plane-" tary system;comprises the internal igear G, "a plurality of angularly'spaced pinion:gears :H, HFI'eandlEP. and a "sun pinion igear J.x-" il he gears H, .H,and .H are rotatably supported on :radial extensions of an arm which'is'secured on the circumference of a crank disc K4. The disc 3K form'sanintegra'l "endportion of (a :normally stationary crank FShfiIfl? Kextending rearwardly therefrom. The shaft K is irotatab'lymounted in :abearing K apo-t 'sitioned in a housing wall K and with its axis ofrotation out of longitudinal alignment with the axis of the drive shaftin any normal position of the latter. A crank pin K projects from thedisc K towards and into the recess E the inner race F of the bearing Fbeing mountedthereon. The sun pinion J is secured on the hub L. of aclutch disc L, which is freely rotatable on the shaft K at the rear ofthe crank disc. As illustrated in Fig. 2, the pinion H is of greaterpitch diameter than the pinions H and H which are shown as of equalpitch diameter.

' through the planetary, system illustrated.

With the above arrangement it will be noted that rotation of the shaft Kwill effect an eccentric movement of the arm K, casing E,

and drive shaft B about the axis of the shaft The source of'power forthe rotation of shaft K l'is the drive shaft B, effected Obviously,'ifthe arm K is fixed in position and the internal gear G rotated, thenthe sun pinion J Willfreely revolve on the shaft K and the drive shaftwill be maintained in the ffsame positioni When, however, the sun pinionis held stationary and the internal gear -.rotated, the arm -K' andshaft K will be imoved aboutthe axisof the shaft K This rotativemovement "through the crank pin K effects an eccentric movement of theinternal,

, gear and drive shaft WVhenthe latter isinitially-enga-ged with theshaft C as shown, an eccentric movement through 180 will disengagetheshaft'B and C and operatively engage -the shafts B and D The eccentric-movement willcontinue returning the shaft B towards its initialposition unless provisions are made for quicklyreleasing the sun pinionand engaging the arm K at the secondengaging position.

By the present invention, mechanism is provided for controlling theshifting movement. In the embodiment illustrated, a disc M is secured tothe shaft K adjacent to the clutch disc L. The disc M is provided withperipheral notches M, M M M angularly spaced. 90.fromone another andadapted to r be intercepted by a trip lever P.

The clutch discL, which is rotatable on the shaft .K is surrounded by aclutch consisting of two semi-circular members L and L Thecircumferential portion of the clutch disc isarranged to fitwithin aslot L atthe inner side'of .each of the clutch members and the latterare held in friction contact with the clutch'disc and connected to oneanother by bolts L and compression springs L as shown jinFig. 4;. Theperipheral portions of the ,;clutch members are formed with notches L 2LL and L and also adapted to be inter- 'cepted by the lever Pu This leverispivotal- -ly mounted at P on a solenoid supporting, V frame '1. Asupporting tube P 'extends from. the frameP to .carry a solenoid coil Pof a well known form. A magnetic arm'a-' ture or core P is positioned inthe tube P and arranged to be drawn axially therein when the solenoid Pis energized. The armature P has a slotted connection at its outer endto theupper end of the trip lever'P to eifect a pivotal movement of thelatter between a positionin which a lever finger P" can intercept thedisc M and a second posi-' tion in which a lever finger P can interceptone of the clutch members L? or L The armature is normally held in theposition il-' lustrated in Fig. 1 by the actioneof a com- I pressionspringl arranged on the armature between the enlarged outer end thereofand the end of the tube P lViththe'foregoing parts constructed andarrangedas described and the drive shaft B rotating in the directionindicated by the arrow in Fig. l and the helical gear C in en gagementwith the gear C, the sun pinion J of the planetary system and the clutchmechanism described rotate freely on the shaft K provided the trip leverP is in. the

position shown in Fig. 1. In that position,

the finger P is positionel within the notch l\ to hold the disc M andshaft K fixed in position. When it is desired to shift the driveshaft toits-lower position in which the worm D and worm gear D engage, thesole--noid coil I" is energized by means hereinafter described and thearmature P movesaxially therein. By this movement the trip lever iswithdrawn from engagement with the disc 'Mand pivot-ally moved sothatthe finger P intercepts an adjacent notch in theiclutch. lVhen this-hastaken place, the sun pinion J becomes fixed in position and the discM,

. 1. When this position hasbeen reached, the

solenoid must be deenergizedimmediately to prevent further eccentricmovement of the gear G. The deenergizaton of the solenoid permits thearmature? to move outwardly out of the action of the spring P and the resulting pivotal movement of the ,trip lever brings the latter into'aposition in which it intercepts the notch-M which has been dis placed180 from the position shown in Fig.

a. The arm K being, again fixed in position, the clutch and sun gear arefree to rotateonthe shaft K until, the-next shifting movement takesplace. 1

During'the action described in which the worm. and worm gear arerelatively moved into an engaglng position, it often happens that therelative: position of the partsiis such that the gear teeth will. notproperly mesh. When-the worm andworm gear are formed with teeth ofstandardrfornr and so positioned that the tooth outer faces are broughtinto abutting contact by the shiftinginovement, it will be obviousthatif further relative movement occurs in the same direction, distortion ofthe parts will occur unless suitable-provisions are made. fortemporarily restricting or rendering inefiective the force bringing thegears into contact; The specific clutch mechanism heretofore-describedis provided for this purpose and the clutch construction permitsslippage between the clutch. disc and clutch until the worm threadadvances 'sur'iiciently to bein the proper meshing position.

In lieu of, but preferablyin addition to, the clutch mechanismdescribed-,each of the engaging gearsare provided with t'eeth ofmodified standard form to aid in the proper meshing'of the gears. Eachof the threads and teeth of the engaging gears have their outer face dinclined towards the working face-d of the gear. As shown in Fig; .6,the line of intersection or the working edge: (Z between the workingfaced of the wormathreadand its original outertaced? is determined andthe thread isthen'. milled to a plane intersecting the working edgeandat'an angle otlOtoZO- with theoriginal" outer face (Z The teeth of thegears G,- C and D" aresimilarlyformed.

The resulting faces (Z when brought into contact slide relatively to oneanother and'the eccentric movement of the worm continuing causes thewormv gear to more rearwardly,

thereby permitting the worm thread to siide into its properengagingposition. v

The present invention also comprises automatically operating means forcontrolling the shifting movement described. As shownparticularly inFigs. 1 and 5 theshaft K is provided with a narrowed extension. K onwhich a cam Q is secured. Surroundingthe cam is a. rectangular channelframe Q supported from the housing K by insulated bolts Q Three sides oftheframe areprovided-with.

lifting members 0, 0 and O ,'respectively, each' formed of insulatingmaterial andconsisting of a pin 0 having a collar 0 thereon which isslidably mounted. in the 'fra-meQf at points equi-spaced irom the axisof the shatt K. The upper end of each pin is arranged to-contact withthe underside of a correspond.- ing 'flat spring R,.R or R having aninsulatedpost connection R with the frame adjacent one end.' Theopposite end of the spring It" carries a contact point R at itsunderside which is normally contacting with the frame. In theconstruction shown the lifting members 0, O and O are angularly spacedfrom'one another and correspond to the upper, neutral and lowerpositionsof the drive shaft. The springs and'R' a te similarly providedwith contact points R andR, respectively. Thetourth side of the frame-Q!is connected; by aconductorl to a terminal post '1 mounted on'and;insulated from the housing K4. A similar. terminal postT is providedwith a. conductor 2' in which. asource oi electricalienergy T ispositioned and which; is connected by branch conductors 3,4; and 5=tothe springsR ,IRFPandR respectively; Operating: switches S, S and Sarepositioned in the conductors 3; 1 and 5, respectively; The terminalposts LT and T areconnected to. opposite: ends of-thesolenoid -coilPfiwhereby the latter will be energized when any one of thefirame-circuitsare closed.

With. the; control provisions arranged as 1 describedand a shifting: ofthe: drive shaft from the position shown in Fig. 1;-.to;-its..lowerposition desired, the cam: Q;.Wi;ll be in'the position indicated in Fig5;. the1switch. S isthenzclosed to establish an electrical: circuitthrough the conductor 1, firame Q, contact point-.RP, spring"R conductor5,. and conductor. 2, thereby energizingthe solenoid P to operatethet'rip lever: q'lhe shaft K rand cam Q is'thereby rotated, from itsupperpositionthrough: an angleof 180 on which point its circuit isautomaticallyinterrupted when the drive-shaft reaches the desiredposition. While in accordance with theprovisionsof the statutes, I haveillustratedandi. described the best form of embodiment 02E myinventionskilledin the art that? changes-vmay be made in the form of theapparatus-disclosed with- .nowknow to me, it will be a:apparent'to=thoseout departing-from the-spiritofmy invention asset forth in the appended"claims and that in some cases certain features of my inventionmay136118664130 advantage without a corresponding use of other features. aHavingnow: described 'my; invention what I, claim asnew and desirerto.secure by Letters Patent,is H V 1. In apparatus of the characterdescribed, a..rotat'able driving-2 element,- a: rotatable driven.element adaptedto be operativelyconr nected tov said driving element,and; means for moving one ofsaid' elements throughan ecing one ofsaidelementslthrough'an eccentric orbit to efl'ectsaid'conneetiom saidIastniencentric orbitto. eiiect said connection, said last mentionedmeans. comprisingzprovislons tioned means comprising a plurality ofparts having a friction connection, whereby relative movement'betweensaid parts effects a temporary interruption ofsaid connecting movementuntil said elements are relatively arranged in a predetermined manner.

3. In apparatus of the character described, a rotatable gear element,a-second rotatable gear element adapted to be operatively connected tosaid first element, and planetary gear means for moving said firstmentioned gear element eccentrically to eflect said connection, saidlast mentioned means comprising friction clutch provisions formomentarilyinterrupting said connecting movement until said gearelements are in a properposition to mesh. a

4. In apparatusof the characterdescribed, a normally rotating drivingshaft, a plurality of rotatable driven shafts adapted to be alternatelyconnected. to said driving shaft, and means for moving said drivingshaft into 'a rotatable driving element, a rotatable driven operativeengagement with oneof said driven shafts spaced therefrom, said meanscomprising aplanetary gear system, the internal gear of said systembeing secured on said driving shaft, a sun gear. freely rotatableaboutan axis oif-setfrom said driving shaft, a plurality of pinion gearsin operative engagement with said internal gear'and sun gear,

and friction means forholding said sun gear fixed 1n pos tion to effectan eccentrical move ment ofsaid internal gear about said sun gear oncontinued rotation of said driving shaft, said friction connection beingrendered ineffective 'by excessive strain during said connectmgmovement. a

- 5. Apparatus of-the character described,

a rotating driving element, a rotatable driven element normally out ofengagement with andadapted to be connected to saiddriving element, meansfor connecting said driving element and sa1d driven element, said meanscomprising a planetary gear system, one of the elements of-said systembeing movable eccentrically relative to a second element of said systemto effect said connection, and means for decreasing the stresses betweensaid driving and driven elements on said con DQCtIOIL' 1 6. In apparatusof the character described,

7 a rotatable driving element, a rotatabledriven element adapted to beoperatively connected to said driving element, means 'for moving one ofsaid elements through an eccentric orbit to effect said connection, andmeans for automatically interrupting said movement when said elementsare connected.

- 7'. In apparatus of the character described, a rotatable drivingelement, a rotatable driven element normally spaced from and adaptedtobe connected to said driving element,'electro-magnetically controlledmeans for moving one ofs'aid elements eccentrically to effect saidconnection, and means for automatically a rendering saidelectro-magnetic means inoperative after a predetermined eccentricmovement of said element.

8. In apparatus of thecharacter described, a rotatable driving element,arotatable driven element normally spaced from and adapted to beconnected to said driving element,

means utilizing the power of said driving element for moving the lattereccentrically to efiect saidconnection, said means comprisinga shafteccentrically mounted relative to said driving element, and means fornormally holding said shaft fixed in position to prevent said drivingelement moving .eccentricallyf relative thereto, and electro-magneticmeans for releasing saidshaft to effect said move--. ment, and means forautomatically render ing said electro'magnetic means inoperative after apredetermined movement of said shaft. 7 I

' 9. In apparatus of the character described,

eccentric movement of said element, a conducting frame surrounding saidcam, spring contacts mounted at angularly spaced points on said frameand normally in contact there- :with, lifting pins mounted in said frameadjacent said contacts and arranged tobe actuated by said cam,conductorsconnecting said frame and contacts withsaid-electromagneticmeans, whereby said cam and-lifting pins coact to render saidelectromagnetic means in operative at predetermined points in the pathof rotation of said cam.

.10. In apparatus of the character described, a normally rotatingdriving shaft, a rotatable driven shaft normally 1 out of engagementwith said driving shaft and'adapted to be operatively connected thereto,a planetary gear mechanism operatively connected to and having anelementmounted on said driving shaft, means for effecting aneccentric movementof said element to operatively connect 7 said shafts, and frictionclutch provisions operatively associated with said means and saidplanetary gear mechanism and operable to interrupt said eccentricmovement while said shafts are in a predetermined relative position. 7'7 V 11. In apparatus of the character described,

a normally rotating driving shaft, a rotatable J driven shaft normallyout of engagement with said driving shaft and adapted to be operativelyconnected thereto, a planetary gear mechanism operatively connected toand havingan'element mounted on saiddriv-ing of Berkshire and State ofMassachusetts, this 3rd day of August, A. D. 1929.

FREDERICK A. PEARSON.

